When Jenny Slate and Gillian Robespierre made the snort-funny and unexpectedly touching Obvious Child, they were on the cusp of the paradigm shift in which the culture suddenly realized that female characters could be occasionally crude and rawly emotional without the world coming to a sudden end. Now, “Girls” having come and gone, the success of chaos comedies like “Broad City” is a well-established fact and Jennifer Aniston is mostly sticking to water ads and the occasional bit part in party flicks. This leaves the landscape feeling more wide open for brasher young female comedians to re-engineer romantic and relationship comedies to their own specifications.

Interestingly, that results in a movie like Landline feeling something like a blast from the past. In one sense, that’s literal. The setting in Manhattan, circa 1995, meaning in part that people drink Zima and can also smoke without being socially ostracized. Slate plays Dana, a twenty-something flibbertigibbet who theoretically works at Paper magazine but really is just working on herself. Although Dana’s engaged to Ben (Jay Duplass), a good-natured sort whose name tag should read Nice Guy Cuckold, she is starting to get cold feet, romantically. That’s when her old college buddy Nate (Finn Witrock), a blithely seductive sort with suspiciously sharp-angled cheekbones, enters the picture and gets Dana all confused about her romantic priorities.

Slate’s snort-honk of a laugh and general air of likeable and well-meaning befuddlement prop up the slightly mechanical recitations of that plotline. But the tangents tossed out by this screenplay—by Elisabeth Holm and director Robespierre—are ultimately more interesting. Dana’s teenage sister Ali (Abby Quinn) is busy experimenting with drugs and clubbing and the limits of their parents’ patience with her eye-rolling antagonism when she discovers a possible secret about their father. As Dana becomes more disengaged from a confused Ben, the closer she gets to Ali and by extension a second adolescence. Floating too far out on the periphery are Ali and Dana’s parents, Pat (Edie Falco) and Alan (John Turturro). We are given just enough of their other lives, hers in the punch-and-grapple city politics of the Giuliani years and his as an ad man aspiring to be a playwright, to be frustrated by how little we see. Falco’s vinegary snap clashes perfectly with Turturro’s droll forbearance, laying the groundwork for a volatile relationship that’s clearly worked out just right for years until suddenly it hasn’t.

On paper, Landline doesn’t throw a lot that’s new into the commitment-freakout romantic-comedy template. The embarrassment-humor factor that Robespierre and Slate used to such advantage in Obvious Child is abundantly in evidence from the first scene—a poorly planned bout of sex in the outdoors that involves poison ivy—and is cleverly deployed throughout this swift-paced comedy. But also in evidence are some minuses, particularly the overemphasized nods to the era’s cultural artifacts, from PJ Harvey to Blockbuster and eyebrow rings.

More problematic is the movie’s lack of interest in consequences. Like a guardian who’s a little too eager to be their ward’s best friend, the movie wants to let its characters play on the dark side of unlikeability and risky behavior but without working in the possibility of blowback. That’s one thing when talking about an affair, quite another when heroin is presented as some novelty drug to try on a lark.

Funny, knowing and tart, Landline has quite a bit more courage than the average relationship comedy when it comes to showing its protagonists in less-than-sympathetic situations of their devising. But if it had followed that courage through and not kept trying to let those characters off the hook, it could have been downright revolutionary.